It's been around since last year but not everyone seems to get it. I opted out last year because a couple of things didn't work how I wanted them to. They opted me back in a few days ago and it took me ages to find the forum thread explaining how to opt out, so in case anyone else wants to opt out, here's how to do it:

Click on Sell an Item. Type car into the field where it asks what you're selling. You may get a few options to choose from so click on one of them, then you'll get a message saying the new format isn't available for that category, but there'll be a link for you that says "use classic tool" (or something similar).